One well-known type of window treatment is the honeycomb window shade. In a honeycomb window shade is made up of an interconnected series of rows of cells of a thin foldable material suspended from a headrail. There are a variety of apparatus and methods known in the art for manufacturing such honeycomb shades. One technique, disclosed in U.S. Pat. No. 4,450,027 to Colson, involves folding a continuous strip of fabric into a tube, applying adhesive to the exterior of the tube and then winding the tube onto a rotating rack so that the adjacent windings of the stacked tube are bonded together to form a honeycomb array or stack of cells. The stacked array of cells is then cut and the cellular structure removed from the tube. U.S. Pat. No. 5,228,936 and U.S. Pat. No. 5,714,034 to Goodhue is directed to another apparatus and method for making a cellular structure. In these patents, a continuous process of folding a strip of material to form a tubular structure, applying adhesive to the tubular structure, cutting the strip including adhesive and stacking the cut strips to form a cellular structure is disclosed. One disadvantage with such a process and apparatus is that since the adhesive is applied to the strip of material before cutting, the process requires the further step of chilling or heating the material after the adhesive has been applied to dry or cure the adhesive. This is done so as to reduce the amount of adhesive residue on components located downstream in the process, such as the cutter and feed rollers.
The number of columns of cells in the honeycomb structure may also be varied in their construction by adjusting the folding pattern of the material. For example, U.S. Pat. No. 5,834,090 to Huang discloses a process in which individual strips of material are folded and attached together with an adhesive to create a cellular structure having multiple columns of cells by folding the strip into a variety of configurations before adhesively attaching the sheets together. One problem with this process is that a web is provided, which is folded and stacked, and therefore, different width webs must be utilized for different width window coverings.
The present invention is an improvement on the described devices and processes for making such honeycomb structures which offers several advantages over the existing art that will be evident to those skilled in the art. Some of these advantages are provided below.